Finger-operable dispensing pumps are typically adapted to be mounted on hand-held containers. Such containers are commonly used for liquid or paste products, such as household and automotive cleaners, industrial preparations, and personal care products such as hair sprays, deodorants, colognes, and the like. Typically, some pumps operate to produce a fine mist or atomized spray, and other pumps operate to dispense a quantity of product in a liquid or paste form.
Finger-operable pumps conventionally employ a pump chamber in which is disposed a pressurizing piston that can be actuated by pressing down on an external actuator, button, or plunger which is connected to the piston with a hollow discharge tube or stem. The hollow stem establishes communication between the pump chamber and actuator from which the product is discharged. A spring acts against the piston or actuator to return the piston and actuator upwardly to the elevated rest position when the finger pressure is released.
One type of conventional spray pump package includes a container holding the liquid contents, a pump mounted in the container, an actuator or button mounted on the pump, and a shell or overcap mounted on the container or pump around the actuator. The shell or overcap typically provides an aesthetically pleasing peripheral structure surrounding the upper portion of the pump and actuator. The overcap typically has a suitable notch or opening to accommodate discharge of the spray from the actuator when the actuator is depressed to operate the pump.
In order to reduce the cost of manufacture, designs have been proposed in which the actuator and surrounding shell are initially molded together as a unitary structure. The unitary structure is subsequently mounted over the container to be supported by the container or pump housing, and the initial user must break the actuator away from the surrounding shell in order to operate the pump. See, for example, U.S. Pat. No. 4,095,725 and U.S. Pat. No. 3,223,287.
Conventional, molded unitary actuator/overcap systems have some drawbacks and disadvantages. For example, the user must initially break the actuator from the surrounding shell in order to actuate the pump for the first time. The unitary connection or connections between the actuator and the surrounding shell must be readily broken by the user without requiring an unusually high amount of force and/or without requiring that force be directed along a particular line of action that might be awkward for the user.
The manufacture of such a conventional, unitary actuator/overcap must be relatively precisely controlled in order that the frangible connections between the actuator and surrounding shell can be made sufficiently small so that the frangible connections can be broken by application of force which is not too large. If the amount of force required to break the actuator away from the surrounding shell is too large, then a user may find it extremely difficult, or perhaps impossible, to effect breakage and operate the pump. However, if a relatively small force can cause the actuator to be broken away from the surrounding shell, then the actuator may be prematurely broken from the surrounding shell as a result of impacts on the package during manufacturing, shipping, storage, and handling.
It is relatively costly to employ manufacturing techniques for providing a unitary actuator/overcap structure that will permit the actuator to be separated from the overcap when subjected to force which is not too large, but which prevents actuator separation when the force is less than a predetermined lower limit. The manufacturing cost is high, both in the initial cost for the molding equipment as well as in the cost for manufacturing operations, including inspection, testing, etc.
Some pump actuator designs, such as those disclosed in the U.S. Pat. No. 3,367,540, require that the user, during the initial use of the pump, manipulate the package in such a way as to break a frangible connection or connections between the actuator and a peripheral base portion and further manipulate the actuator so as to seat the actuator on the pump discharge tube or stem. The manufacturer must essentially rely on the user to properly manipulate the device with appropriate alignment and with appropriate force application to fully seat the actuator on the pump discharge tube.
In any event, with those designs wherein the user must initially break the actuator from a portion of a unitary molded structure, the user may act somewhat tentatively while initially applying force to the actuator, and the initial operation may not be as smooth or as complete as would be desired. In some cases, the initial actuation may be too slow. A slow actuation speed could result in a slower velocity of the product flow, and that could result in a poor spray.
It would be desirable to provide an improved assembly and manufacturing process for such spray pump packages. It would be advantageous to provide an improved structure which would not require a special hood to cover the top of the actuator to protect the actuator from being prematurely actuated during shipping or storage because the elimination of such a hood would reduce the product cost.
In addition, it would be beneficial if such an improved design could accommodate relatively long actuation strokes (e.g., 7-9 mm) of some pumps.
It would also be beneficial if an improved dispensing package could accommodate incorporation of a more aesthetically pleasing design.
It would also be desirable to provide an improved design of a unitary overcap structure, including an actuator and a surrounding shell, which could be relatively easily molded and that would facilitate economical manufacture, high production quality, and consistent operating parameters unit-to-unit with high reliability.
Such an improved design should also desirably provide a system which can be assembled and installed without expensive, specialized equipment.
Preferably, such an improved system should accommodate designs which will permit assembly by automatic equipment and which will not require the user to effect a final assembly step or otherwise manipulate the system in a way that would be necessary to place the system in condition for normal use.
Such an improved system should desirably accommodate designs which would protect the user's finger from injury or discomfort during actuation of the pump. To this end, such an improved design should minimize, if not eliminate, sharp edges, even after separation of the actuator from the surrounding shell.
It would also be beneficial if such an improved design would operate with little or no scraping of moving parts so as to minimize or eliminate noise, chatter, and wear.
The present invention provides an improved system which can accommodate designs having the above-discussed benefits and features.